If you multiply an object's weight by its height, what value do you compute?

Which kind of matter can be homogenous or heterogenous ?

Eduardwww [97]

A homogeneous mixture has the same uniform appearance and composition throughout. Many homogeneous mixtures are commonly referred to as solutions. A heterogeneous mixture consists of visibly different substances or phases. The three phases or states of matter are gas, liquid, and solid.
Hope this helps you!

5 0

3 years ago

A 2.00-g sample of a large biomolecule was dissolved in 15.0 g carbon tetrachloride. the boiling point of this solution was dete

Katarina [22]

We will use boiling point formula:

ΔT = i Kb m

when ΔT is the temperature change from the pure solvent's boiling point to the boiling point of the solution = 77.85 °C - 76.5 °C = 1.35

and Kb is the boiling point constant =5.03

and m = molality

i = vant's Hoff factor

so by substitution, we can get the molality:

1.35 = 1 * 5.03 * m

∴ m = 0.27

when molality = moles / mass Kg

0.27 = moles / 0.015Kg

∴ moles = 0.00405 moles

∴ The molar mass = mass / moles
= 2 g / 0.00405 moles
= 493.8 g /mol

5 0

3 years ago

How many valence electrons does Nitrogen have?

irinina [24]

Answer:

5 valence electrons

Nitrogen has a total of 5 valence electrons

Explanation:

6 0

3 years ago

Under certain conditions the rate of this reaction is zero order in dinitrogen monoxide with a rate constant of 0.0067·Ms−1: 2N2

choli [55]

Answer:

5.6 seconds

Explanation:

The reaction follows a zero-order in dinitrogen monoxide

Rate = k[N20]^0 = change in concentration/time

[N20]^0 = 1

Time = change in concentration of N2O/k

Initial number of moles of N2O = 300 mmol = 300/1000 = 0.3 mol

Initial concentration = moles/volume = 0.3/4 = 0.075

Number of moles after t seconds = 150 mmol = 150/1000 = 0.15 mol

Concentration after t seconds = 0.15/4 = 0.0375 M

Change in concentration of N2O = 0.075 - 0.0375 = 0.0375 M

k = 0.0067 M/s

Time = 0.0375/0.0067 = 5.6 s

4 0

3 years ago

How much energy (heat) is required to convert 248 g of water from 0 oC to 154 oC? Assume that the water begins as a liquid, that

Nuetrik [128]

Answer:

The total heat required is 691,026.36 J

Explanation:

Latent heat is the amount of heat that a body receives or gives to produce a phase change. It is calculated as: Q = m. L

Where Q: amount of heat, m: mass and L: latent heat

On the other hand, sensible heat is the amount of heat that a body can receive or give up due to a change in temperature. Its calculation is through the expression:

Q = c * m * ΔT

where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the change in temperature (Tfinal - Tinitial).

In this case, the total heat required is calculated as:

Q for liquid water. This is, raise 248 g of liquid water from O to 100 Celsius. So you calculate the sensible heat of water from temperature 0 °C to 100° C

Q= c*m*ΔT

$Q=4.184\frac{J}{g*C} *248 g* (100 -0 )C$

Q=103,763.2 J

Q for phase change from liquid to steam. For this, you calculate the latent heat with the heat of vaporization being 40 and being 248 g = 13.78 moles (the molar mass of water being 18 g / mol, then $\frac{248 g}{18 \frac{g}{mol} } =13.78 moles$ )

Q= m*L

$Q=13.78moles*40.79 \frac{kJ}{mol}$

Q=562.0862 kJ= 562,086.2 J (being 1 kJ=1,000 J)

Q for temperature change from 100.0 ∘ C to 154 ∘ C, this is, the sensible heat of steam from 100 °C to 154°C.

Q= c*m*ΔT

$Q=1.99\frac{J}{g*C} *248 g* (154 - 100 )C$

Q=25,176.96 J

So, total heat= 103,763.2 J + 562,086.2 J + 25,176.96 J= 691,026.36 J

<u><em>The total heat required is 691,026.36 J</em></u>

8 0

3 years ago